Downhole tool for prevention of solids accumulation on a downhole pump

Abstract

A downhole tool can include a housing assembly including a screen, a fluid discharge housing and an annular packer, a sucker rod being received in a flow passage extending through the housing assembly. A method can include positioning a downhole tool above a pump, sealingly engaging an annular packer of the downhole tool with an interior of a tubular string, and operating the pump, thereby flowing a fluid and solids through an annulus formed between the downhole tool and the tubular string above the annular packer. A system can include a downhole pump configured to pump a fluid through a tubular string, and a downhole tool in the tubular string and positioned above the pump, the downhole tool comprising an annular packer that sealingly engages an interior of the tubular string, a fluid discharge housing connected above the annular packer, and a screen connected above the fluid discharge housing.

Description

BACKGROUND

[0001] This disclosure relates generally to operations performed and equipment utilized in conjunction with a subterranean well and, in an example described below, more particularly provides a downhole tool for use with a downhole pump.

[0002] In well fluid production operations, a downhole pump is frequently used to flow fluids to surface through a tubular string. Such downhole pumps can include reciprocating rod pumps, electric submersible pumps, progressing cavity or positive displacement pumps, etc. Profitability of the production operations can depend on many factors, such as, efficiency of the fluid pumping, requirements to maintain or replace the pump due to malfunction or wear, etc.

[0003] Therefore, it will be readily appreciated that improvements are continually needed in the art of enhancing efficient and economical operation of downhole pumps. The present disclosure provides such improvements, which may be used with a wide variety of different well configurations, production operations and downhole pumps.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 is a representative partially cross-sectional view of an example of a well system and associated method which can embody principles of this disclosure.

[0005] FIG. 2 is a representative cross-sectional view of an example of a downhole tool that may be used in the FIG. 1 system and method.

[0006] FIG. 3 is a representative cross-sectional view of the downhole tool in a fluid production operation.

[0007] FIG. 4 is a representative cross-sectional view of the downhole tool with fluid and sand / solids production.DETAILED DESCRIPTION

[0008] Representatively illustrated in the accompanying drawings is a downhole tool and associated system and method which can embody principles of this disclosure. However, it should be clearly understood that the tool, system and method are merely one example of an application of the principles of this disclosure in practice, and a wide variety of other examples are possible. Therefore, the scope of this disclosure is not limited at all to the details of the tool, system and method described herein and / or depicted in the drawings.

[0009] The downhole tool in this example is a purpose-built tool for sucker rod pump or reciprocating rod pump systems, installed above the pump discharge to combat the challenges posed by sand and solids. It is designed to optimize pump runtime, reduce wear, and offer a simple, effective solution that helps maintain well productivity even in sand-prone environments.

[0010] By preventing sand from settling on top of the pump during the downstroke (for a reciprocating rod pump) or during shutdown conditions, the downhole tool minimizes the risk of stuck pumps, plunger damage and abrasive wear. The downhole tool extends pump life, reduces workover frequency, and improves production in challenging well conditions.

[0011] Although this example is specifically designed for use with sucker rod pumps, in other examples the downhole tool can be suitably configured for use with progressing cavity pump systems.

[0012] The downhole tool is designed to improve the run time and reduce damage to the pump due to sand fall back. The tool is installed above the pump.

[0013] In every stroke, the liquid flow from the pump discharges to the intake of the downhole tool (which is below a cup packer in this example). Once fluid passes through, it flows between the rods and the inner housing and it is discharged through the screens and discharge ports. Fluid and sand can't flow back onto the pump due to the cup packer.

[0014] In an upstroke, the differential pressure created from the pump allows liquid to flow through and creates turbulence for the sand to be removed and flowed to the surface. In the downstroke, the sand (due to its density) falls back between the screen and interior of the tubing, thereby protecting the pump.

[0015] In one beneficial feature of this example, the downhole tool can be used with any type of pump. In addition, more than one downhole tool can be installed above the pump.

[0016] Referring now to FIG. 1, a representative partially cross-sectional view of an example of a well system 10 and an associated method which can embody principles of this disclosure are depicted. In this example, a tubular string 12 (such as, a production tubing string, a conduit, etc.) is deployed into a wellbore 14. The wellbore 14 is lined with casing and cement, but in other examples sections of the wellbore may be uncased or open hole.

[0017] A downhole pump 16 is installed in the tubular string 12. The downhole pump 16 may comprise any type of downhole pump, such as, a reciprocating rod pump, electric submersible pump, or progressing cavity or positive displacement pump.

[0018] As depicted in FIG. 1, the downhole pump 16 is a reciprocating rod pump. A sucker rod string 18 is connected to the pump 16 for operating the pump. As the sucker rod string 18 is reciprocated alternately upward and downward, a fluid 20 (such as, oil, gas, gas condensates, water, or any combination thereof) is produced from the well (such as, from an earth formation 22 penetrated by the wellbore 14), through the pump 16, and from an outlet of the pump through the tubular string 12 to the surface.

[0019] Unfortunately, solids 24 are also produced with the fluid 20. The solids 24 may comprise sand, fines, cement particles, debris, etc. The pump 16 could be damaged or its operation rendered less efficient if the solids 24 are allowed to settle onto the pump 16 at any time the pump is not flowing the fluid 20 through the tubular string 12 (such as, when the sucker rod string 18 is on a downstroke, or if the pump 16 is temporarily not operating).

[0020] To prevent accumulation of the solids 24 onto the pump 16, a downhole tool 26 is deployed into the tubular string 12 above the pump. The downhole tool 26 can be deployed into the tubular string 12 with the downhole pump 16 and the sucker rod string 18.

[0021] In the FIG. 1 example, the downhole tool 26 includes a screen 28, a fluid discharge housing 30 and an annular packer 32. The screen 28 is connected above the fluid discharge housing 30, which is connected above the packer 32.

[0022] Referring additionally now to FIG. 2, a representative cross-sectional view of an example of the downhole tool 26 is depicted. For convenience, the downhole tool 26 is described below as it may be used with the FIG. 1 system 10 and method, but in other examples the FIG. 2 downhole tool 26 may be used with other systems and methods.

[0023] As depicted in FIG. 2, the downhole tool 26 includes a generally tubular outer housing assembly 34. The outer housing assembly 34 includes the screen 28, the fluid discharge housing 30 and the annular packer 32. A flow passage 36 extends axially through the outer housing assembly 34.

[0024] In this example, the flow passage 36 is dimensioned to accommodate the sucker rod string 18 therein. A bushing 38 is positioned in an upper housing 40, and another bushing 42 is positioned in a lower housing 44. The bushings 38, 42 provide for sliding, reciprocating movement of the sucker rod string 18 relative to the outer housing assembly 34.

[0025] The screen 28 in this example is of the type known to those skilled in the art as a tubular wire-wrapped well screen. Other types of screens (such as, wire mesh, sintered, etc.) may be used in other examples.

[0026] The fluid discharge housing 30 includes multiple ports 46 that permit fluid communication between the flow passage 36 and an exterior of the fluid discharge housing. When used in the FIG. 1 system 10 and method, the ports 46 provide for fluid flow between an interior annulus formed radially between the outer housing assembly 34 and the sucker rod string 18, and an exterior annulus formed between the outer housing assembly and the tubular string 12.

[0027] Note that the ports 46 are inclined axially downward toward the exterior of the fluid discharge housing 30. Thus, the ports 46 are inclined toward the packer 32 in an outward direction. This inclination of the ports 46 aids in preventing back flow of the solids 24 into the flow passage 36, as described more fully below.

[0028] The packer 32 in the FIG. 2 example is of the type known to those skilled in the art as a cup packer, and is dimensioned to sealingly engage an interior surface of the tubular string 12 in the FIG. 1 system 10 and method. Other types of packers or annular seals may be used in other examples.

[0029] One or more ports 48 are formed through a sidewall of the lower housing 44. The ports 48 provide for entry of the fluid 20 and solids 24 into the flow passage 36 from the outlet of the pump 16.

[0030] Referring additionally now to FIG. 3, a representative cross-sectional view of the downhole tool 26 in a fluid production operation is depicted. The downhole tool 26 is shown in FIG. 3 as it is deployed into the tubular string 12 in the FIG. 1 system 10 and method, but for illustrative clarity the other elements of the FIG. 1 system are not shown.

[0031] In the FIG. 3 example, the fluid 20 and solids 24 are flowed by the pump 16 (not shown in FIG. 3) to the downhole tool 26. The fluid 20 and solids 24 flow into the ports 48 and then upward through an interior annulus 50 formed radially between the outer housing assembly 34 and a sucker rod 52 of the sucker rod string 18. The packer 32 seals against an interior surface of the tubular string 12, thereby blocking fluid flow through an exterior annulus 54 formed radially between the outer housing assembly 34 and the tubular string.

[0032] The upward flow of the fluid 20 and solids 24 occurs while the pump 16 is operating (such as, when the sucker rod string 18 is on an upstroke, or the pump is otherwise operating to pump the fluid and solids). After entering the interior annulus 50, the fluid 20 and solids 24 flow outward to the exterior annulus 54 via the screen 28 and the ports 46 of the fluid discharge housing 30.

[0033] When the pump 16 is not operating, the solids 24 can descend through the interior of the tubular string 12 and can accumulate in the exterior annulus 54. Note that the downward inclination of the ports 46 in the fluid discharge housing 30 aids in preventing the solids 24 from displacing into the interior annulus 50 via the ports.

[0034] Referring additionally now to FIG. 4, a representative cross-sectional view of the downhole tool 26 with fluid 20 and sand / solids 24 production is depicted. As viewed in FIG. 4, the solids 24 have accumulated in the exterior annulus 54 while the pump 16 was not operating.

[0035] As depicted in FIG. 4, the pump 16 is then operated again (for example, on an upstroke of the sucker rod string 18), and the fluid 20 and solids 24 are again flowed to the surface via the tubular sting 12. Beneficially, the fluid 20 is flowed outward through the ports 46 in the fluid discharge housing 30, thereby carrying the solids 24 previously accumulated in the exterior annulus 54 toward the surface. Thus, the solids 24 are flushed from the interior of the tubular string 12 when the pump 16 is operated.

[0036] It may now be full appreciated that the present disclosure provides significant advancements to the art of enhancing efficient and economical operation of downhole pumps. In an example described herein, the downhole tool 26 prevents the solids 24 from falling back onto the pump 16 when the pump is not flowing the fluid 20 to the surface, and provides for lifting the solids to the surface when the pump is again operated.

[0037] The present disclosure provides to the art a downhole tool 26. In one example, the downhill tool 26 can include a tubular outer housing assembly 34 comprising a screen 28, a fluid discharge housing 30 and an annular packer 32. A flow passage 36 extends axially through the outer housing assembly 34. The flow passage 36 is configured to receive a sucker rod 52 therein.

[0038] The fluid discharge housing 30 may be connected axially between the screen 28 and the annular packer 32. The annular packer 32 may be configured to block fluid flow through an annulus 54 formed between the outer housing assembly 34 and a tubular string 12 surrounding the outer housing assembly 34.

[0039] The fluid discharge housing 30 may comprise at least one port 46 that permits fluid communication between the flow passage 36 and an exterior of the outer housing assembly 34. The port 46 may be axially inclined. The port 46 may be outwardly inclined in a direction toward the annular packer 32.

[0040] The downhole tool 26 may include first and second bushings 38, 42 at respective first and second opposite ends of the outer housing assembly 34. The first and second bushings 38, 42 may be configured to slidingly engage the sucker rod 52.

[0041] A method of preventing accumulation of solids 24 on a downhole pump 16 is also provided to the art by the present disclosure. In one example, the method can comprise: positioning a downhole tool 26 above the downhole pump 16, the positioning step including sealingly engaging an annular packer 32 of the downhole tool 26 with an interior of a tubular string 12; and operating the downhole pump 16, thereby flowing a fluid 20 and the solids 24 through an annulus 54 formed between the downhole tool 26 and the tubular string 12 above the annular packer 32.

[0042] The operating step may include reciprocating a sucker rod 52 that is received in a flow passage 36 extending axially through the downhole tool 26.

[0043] The flowing step may include flowing the fluid 20 through at least one port 46 of a fluid discharge housing 30 connected above the annular packer 32. The flowing step may further comprise flowing the fluid 20 axially downward through the at least one port 46.

[0044] The method may include operating the downhole pump 16, thereby flowing the fluid 20 outward through a screen 28 of the downhole tool 26. The method may further include connecting a fluid discharge housing 30 axially between the screen 28 and the annular packer 32.

[0045] The flowing step may include flowing the fluid 20 between an outer housing assembly 34 of the downhole tool 26 and a sucker rod 52 received in the outer housing assembly 34.

[0046] The present disclosure also provides to the art a system 10 for use with a subterranean well. In one example, the system 10 can comprise: a tubular string 12 deployed in the well; a downhole pump 16 configured to pump a fluid 20 through the tubular string 12; and a downhole tool 26 in the tubular string 12 and positioned above the downhole pump 16. The downhole tool 26 includes an annular packer 32 that sealingly engages an interior of the tubular string 12, a fluid discharge housing 30 connected above the annular packer 32, and a screen 28 connected above the fluid discharge housing 30.

[0047] A flow passage 36 may extend axially through the screen 28, and a sucker rod 52 may extend through the flow passage 36. An outlet of the downhole pump 16 may be in fluid communication with an annulus 50 formed between the screen 28 and the sucker rod 52.

[0048] The fluid discharge housing 30 may include at least one port 46 that permits fluid communication between an interior and an exterior of the fluid discharge housing 30. The port 46 may be outwardly inclined in a direction toward the annular packer 32.

[0049] The system 10 may include first and second bushings 38, 42 at respective first and second opposite ends of the downhole tool 26. The first and second bushings 38, 42 may slidingly engage a sucker rod 52.

[0050] Although various examples have been described above, with each example having certain features, it should be understood that it is not necessary for a particular feature of one example to be used exclusively with that example. Instead, any of the features described above and / or depicted in the drawings can be combined with any of the examples, in addition to or in substitution for any of the other features of those examples. One example's features are not mutually exclusive to another example's features. Instead, the scope of this disclosure encompasses any combination of any of the features.

[0051] Although each example described above includes a certain combination of features, it should be understood that it is not necessary for all features of an example to be used. Instead, any of the features described above can be used, without any other particular feature or features also being used.

[0052] It should be understood that the various embodiments described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of this disclosure. The embodiments are described merely as examples of useful applications of the principles of the disclosure, which is not limited to any specific details of these embodiments.

[0053] In the above description of the representative examples, directional terms (such as “above,”“below,”“upper,”“lower,”“upward,”“downward,” etc.) are used for convenience in referring to the accompanying drawings. However, it should be clearly understood that the scope of this disclosure is not limited to any particular directions described herein.

[0054] The terms “including,”“includes,”“comprising,”“comprises,” and similar terms are used in a non-limiting sense in this specification. For example, if a system, method, apparatus, device, etc., is described as “including” a certain feature or element, the system, method, apparatus, device, etc., can include that feature or element, and can also include other features or elements. Similarly, the term “comprises” is considered to mean “comprises, but is not limited to.”

[0055] Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the disclosure, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to the specific embodiments, and such changes are contemplated by the principles of this disclosure. For example, structures disclosed as being separately formed can, in other examples, be integrally formed and vice versa. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the invention being limited solely by the appended claims and their equivalents.

Claims

1. A downhole tool, comprising:a tubular outer housing assembly comprising a screen, a fluid discharge housing and an annular packer; anda flow passage extending axially through the outer housing assembly, the flow passage being configured to receive a sucker rod therein.

2. The downhole tool of claim 1, in which the fluid discharge housing is connected axially between the screen and the annular packer.

3. The downhole tool of claim 1, in which the annular packer is configured to block fluid flow through an annulus formed between the outer housing assembly and a tubular string surrounding the outer housing assembly.

4. The downhole tool of claim 1, in which the fluid discharge housing comprises at least one port that permits fluid communication between the flow passage and an exterior of the outer housing assembly.

5. The downhole tool of claim 4, in which the at least one port is axially inclined.

6. The downhole tool of claim 5, in which the at least one port is outwardly inclined in a direction toward the annular packer.

7. The downhole tool of claim 1, further comprising first and second bushings at respective first and second opposite ends of the outer housing assembly, the first and second bushings being configured to slidingly engage the sucker rod.

8. A method of preventing accumulation of solids on a downhole pump, the method comprising:positioning a downhole tool above the downhole pump, the positioning comprising sealingly engaging an annular packer of the downhole tool with an interior of a tubular string; andoperating the downhole pump, thereby flowing a fluid and the solids through an annulus formed between the downhole tool and the tubular string above the annular packer.

9. The method of claim 8, in which the operating comprises reciprocating a sucker rod that is received in a flow passage extending axially through the downhole tool.

10. The method of claim 8, in which the flowing comprises flowing the fluid through at least one port of a fluid discharge housing connected above the annular packer.

11. The method of claim 10, in which the flowing further comprises flowing the fluid axially downward through the at least one port.

12. The method of claim 8, further comprising operating the downhole pump, thereby flowing the fluid outward through a screen of the downhole tool.

13. The method of claim 12, further comprising connecting a fluid discharge housing axially between the screen and the annular packer.

14. The method of claim 8, in which the flowing comprises flowing the fluid between an outer housing assembly of the downhole tool and a sucker rod received in the outer housing assembly.

15. A system for use with a subterranean well, the system comprising:a tubular string deployed in the well;a downhole pump configured to pump a fluid through the tubular string; anda downhole tool in the tubular string and positioned above the downhole pump, the downhole tool comprising an annular packer that sealingly engages an interior of the tubular string, a fluid discharge housing connected above the annular packer, and a screen connected above the fluid discharge housing.

16. The system of claim 15, in which a flow passage extends axially through the screen, and a sucker rod extends through the flow passage.

17. The system of claim 16, in which an outlet of the downhole pump is in fluid communication with an annulus formed between the screen and the sucker rod.

18. The system of claim 15, in which the fluid discharge housing comprises at least one port that permits fluid communication between an interior and an exterior of the fluid discharge housing.

19. The system of claim 18, in which the at least one port is outwardly inclined in a direction toward the annular packer.

20. The system of claim 15, further comprising first and second bushings at respective first and second opposite ends of the downhole tool, and in which the first and second bushings slidingly engage a sucker rod.

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